This invention relates to apparatus for clamping and cutting the rear or lower thread in an embroidery machine having a stitch plate having a stitch hole, a shuttle guide, a shuttle displaceably mounted in the shuttle guide, a slidable thread clamping device and a thread cutting device. Such a machine is disclosed, for example in German patent specification No. 20 65 264, which is incorporated herein by reference.
In that machine a thread clamping and cutting device associated with each shuttle of the machine is driven so as to be displaceable by a rotary mechanism, vertically with respect to the conveying direction of the shuttle.
Each thread clamping and cutting device must have its own individual drive mechanism, in order to ensure separate control thereof, such separate drives being uneconomical of space. Such an arrangement can not be used in a conventional shuttle embroidering machine having a 4/4 ratio, because the space needed for the separate drives is unavailable.
Also, the length of the cut thread is such that the appearance of the embroidery is impaired on the reverse side of the embroidered material and the consumption of thread is unduly high.
Further, the clamping and cutting device is arranged in the region of the shuttle guide, whereby the path of the rear or lower thread is impaired, especially since the known clamping and cutting device penetrates the shuttle carrier.
In the known machine the cutting blade of the cutting device, itself initiates clamping of the thread, and the clamping of the thread depends directly upon the cutting process itself. Thus after the cutting of the rear or lower thread has bean completed, the thread is clamped between a clamping surface of a plate spring and the cutting blade itself. Thus when a new cutting operation is to be carried out the clamping of the thread is stopped and the cut rear or lower thread is released. At embroidery sites which are put out of operation on the needle side, the severed and free-hanging rear or lower thread runs up and down with the shuttle and so is rubbed. Thus, when such an embroidery site is operated again, breakage of the thread or dropped stitches may occur.